Nothing is ever easy with these things....

Discussion in 'Motorized Bicycle General Discussion' started by Finfan, Feb 28, 2009.

  1. Finfan

    Finfan New Member

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    So I got a new coaster brake rear wheel and a new 56 tooth sprocket. I find I need to open up the center hole by about 0.08" and I doubt I can do that evenly with a file. Has anybody found a reliable tool/method to do this in a garage that doesn't have any serious machine tools? Otherwise I am going to have to search out a machine shop.
    Thanks!
    :-||
     
  2. toytime

    toytime New Member

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    That's easy, put a round file in a drill and let it spin. Works really great. You can break the file in half to make it shorter if you want to.
    Just to clarify, put the sprocket in a vice and with the drill spinning press the spinning file against the outer edge and move your drill around and around. It will go fast with the spinning file.
     
    #2 toytime, Feb 28, 2009
    Last edited: Feb 28, 2009
  3. MB-Monkey

    MB-Monkey New Member

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    no fix the dust cover instead on the coaster brake file down the ridge on the outside of the dust cover.
     
  4. Spunout

    Spunout MB Builder Extraordinaire

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    i use a file with one flat side, and one half-moon side. takes 3minutes. AND grind down the outwermost edges of the dust cover. sounds like you've got a coaster brake hub.

    file: $5
    time: 3 minutes. tops.
     
  5. Dave31

    Dave31 Moderator
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  6. Spunout

    Spunout MB Builder Extraordinaire

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    many times, you have to enlarge the sprocket hole to fit over the coaster brake hub, but never on a freewheel hub
     
  7. Finfan

    Finfan New Member

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    Well, part of the problem is that the dust cap is just barely in the way when on, but the sprocket doesn't reach the rest of the hub when it is off. That makes it very difficult to get the sprocket centered. I made an attempt with the dust cover off and I have a 2mm difference side to side on the centering. How much runout can I get away with? It is such a long and tedious process to get the rag joint tightened evenly that I would hate to have to repeat it too many times.
     

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